Study: Old Trees Grow Fastest; Store More Carbon

A western white pine in Kings Canyon National Park, Ca, towers over USGS ecologist Nathan Stephenson.

The study, published in The Journal Nature, looked at the growth rates of hundreds of thousands of trees across hundreds of species.

It found that a tree’s growth rate increases with its size, in some cases adding the mass of a small tree every year.

That has huge implications for the amount of carbon dioxide an older tree can absorb.

“One of the analogies I use is if you’re managing a sports team, you’ve got to know who your star players are." says forest ecologist Nathan Stephenson with the USGS, and the study’s lead author.

"This would be the equivalent of discovering that your 90-year-old players are the stars of the team," he says.

Stephenson says it’s important to note that old trees also die, so the absorption rate of carbon doesn’t necessarily translate into a net increase in carbon storage for an entire forest. An international team of researchers analyzed trees across six continents as part of the study.

This April 2013 photo shows giant sequoia trees dwarfing a visitor in Merced Grove in Yosemite National Park in California. Sequoias are among the largest, oldest trees on earth. Kathy Matheson / AP

Using this new approach to calculate the snow’s water content also means improved forecasts for farms and cities, and even positive benefits for renewable-energy production. The program soon could go statewide — if it gets funded.

A judge ordered the California Department of Food and Agriculture to stop spraying dozens of pesticides. Some environmental groups count this as a win but a UC Riverside researcher warns the move will hurt efforts to fight a damaging citrus disease.

About 9 in 10 of the produce tested for pesticides at California grocery stores, farmer's markets and other outlets had little or no residue, according to the state Department of Pesticide Regulation's 2016 survey.

Amy came to Sacramento from New Hampshire Public Radio (NHPR) where she was Environment Reporter. Amy has also reported for NPR member stations WFAE in Charlotte, WAMU in Washington D.C. and American Public Media's "Marketplace." Read Full Bio